Encapsulated boxes (usually called gloveboxes), routinely utilized e.g., in sterile medicine activities, pharmaceutics preparations, food analysis, and hazards and radioactive contaminatable uses are known in the art. In U.S. Pat. No. 4,251,123 to Brackenbush, a flap or door like solution is offered for use with a radioactive safe glove box. The flaps are however, heavy and gravity sensitive, resilient and stiff, rendering the openings leaky with respect to gases and biohazards. U.S. Pat. Nos. 2,528,332; 2,436,291; 2,803,370; 3,086,674; 4,331,254 and 5,104,206 disclose a few embodiments of a glove-less glovebox, having one or more operator hand access port (OHAP) sealed by either (i) one flexible membrane having a star-like (not a port or aperture-crossing-) centralized aperture into which the hand of the operator is inserted, or (ii) a multilayered stack composed of a few flexible membranes, each of which has a star-like centralized aperture into which the hand of the operator is inserted. The aforementioned apertures are slightly disoriented (e.g., rotated) with respect to each another or slightly dislocated (e.g., decentralized) with respect to each other. The aforesaid embodiments are suitable solely for non-pressurized gloveboxes. U.S. Pat. No. 3,450,450 presents a pressure resistant seal which comprises a means defining an aperture and a plurality of closures members of flexible sheet material, attached in a bulky manner side-by-side to the periphery of the aperture, such that the stacked sheets are set perpendicular to the aperture cross section and a thick sealing. Such an arrangement is not suitable for certain high-pressure gloveboxes, especially animal-treating gloveboxes (e.g., anaesthetic chambers).
It is clear from the above that there is a long felt and unmet need for means and methods to enable a human operator to manipulate with dexterity small mammals in a ventilation hood or anaesthetic chamber without gas escaping from the aforementioned chamber into the surrounding environment.